The Halkey-Roberts clamp is a well-known type of one-piece plastic clamp which is used to close off plastic tubing such as polyvinyl chloride tubing.
While the clamp is in widespread use, certain technical disadvantages are found in the present designs of the clamp. The present clamps comprise a single strip of plastic in which the respective ends are curved towards each other to engage together in a snap-fit, spring relation in which a projection or pair of projections squeezes the tubing shut when the ends of the clamp are snapped together. The tubing can be opened by the separation of the projections when the ends of the clamps are separated.
It is desirable for the clamp in its as-molded, unstressed condition to have ends that are close together so that when large containers of the loose clamps are moved or shaken, the clamps do not hook together by random shaking and movement. At the same time, when this has been done, the tube-squeezing portions of the clamp tend to be close enough together to partially compress tubing placed through the clamp which, over a long period of time, can cause a crease or cleft to develop. This can particularly happen with polyvinyl chloride tubing. This crease can serve as a place where a kink in the tubing can develop during use, which is very undesirable.
As a further disadvantage of current designs of the Halkey-Roberts clamp, as one squeezes the ends of the clamp together to close it into a snap-fit, closed retention, the end of the clamp which carries a retention hook to engage the other end also carries an upstanding flange to facilitate re-opening of the clamp. Persons with long fingernails have substantial difficulty in closing the clamp because of this, while their fingers are pointed generally parallel to the axis of the clamp. Accordingly, such individuals close the clamp with their fingers placed transversely or sideways to the clamp. The effect of this often is to cause a skewing of the clamp ends as they close, leaving the clamp in a closed but twisted, undesirable configuration that may only partially close the tubing and thus permit leakage.
By this invention, an improved squeeze clamp is provided which eliminates the above disadvantages of the presently-used Halkey-Roberts clamp.